JP2021028218A - Controller for all-wheel drive vehicle - Google Patents

Abstract

To provide a controller for an all-wheel drive vehicle capable of preventing the occurrence of vehicle body vibration which is caused by an eigenvalue (a resonant frequency) of an entire drive system and can give discomfort to a passenger, without worsening fuel economy and responsiveness, and without causing cost increase.SOLUTION: A TCU70 comprises: a torque bump occurrence prediction section 72 for predicting whether or not a bump occurs in a torque outputted from an engine 20 and inputted to an entire drive system 3; and a transfer clutch control section 73 for controlling a clamping force of a transfer clutch 41 on the basis of a drive state of an AWD vehicle 5. The transfer clutch control section 73 releases the transfer clutch 41 when a vehicle speed is in a prescribed range, a transmission ratio is in a prescribed range, and the bump has been predicted to occur in the torque inputted to the entire drive system 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a control device for an all-wheel drive vehicle.

Conventionally, all-wheel drive (AWD) vehicles having excellent running performance on steep slopes, rough roads with many irregularities, and slippery road surfaces (for example, snowy roads and muddy roads) have been widely put into practical use. As an all-wheel drive vehicle, a full-time system and a part-time system that switches between two-wheel drive and four-wheel drive as needed are known. In the full-time system, a center differential is provided between the front wheels and the rear wheels to allow the front and rear wheels to be differential, so that four-wheel drive is always realized. On the other hand, the part-time system has, for example, a main drive wheel directly connected to the engine and a slave drive wheel (secondary drive wheel) connected to the engine via a transfer clutch, and the fastening force of the transfer clutch is determined by the road surface condition. The drive force distribution to the slave drive wheel side is adjusted by controlling according to the driving condition and the like, and the two-wheel drive and the four-wheel drive are switched.

Here, Patent Document 1 discloses a driving force control device that suppresses vehicle body vibration caused by twisting of a driving shaft due to fluctuations in driving force distribution and untwisting of the driving force in a four-wheel drive vehicle. More specifically, in the driving force control device described in Patent Document 1, when the driving force distribution to the slave drive wheels is reduced, the change speed of the driving force distribution is limited to reduce the fluctuation amount of the driving force distribution. By doing so, the vehicle body vibration caused by the fluctuation of the driving force distribution is suppressed without reducing the driving force distribution to the slave drive wheels.

Japanese Unexamined Patent Publication No. 2016-16732

By the way, the entire drive system of an all-wheel drive vehicle is mainly composed of, for example, a torque converter (including a lockup clutch, etc.), an automatic transmission (including an input shaft, a chain, a pulley, etc.), a reduction gear, a transfer clutch, and a propeller. It is configured to include a shaft, differential gears (front and rear), a drive shaft (front and rear), and the like. The entire drive system having such a configuration has an eigenvalue (that is, a resonance frequency). Therefore, in response to minute engine torque fluctuations, vibrations may occur in which the vehicle body sways at a level that the occupant notices, which may give the occupant a sense of discomfort.

On the other hand, for example, it is possible to reduce the sensitivity of the drive system by changing the hardware specifications, or to suppress the torque fluctuation of the engine by changing the combustion control of the engine, but these countermeasures deteriorate the fuel efficiency. , Decreased responsiveness, cost increase, etc. are expected to be sacrificed. In the driving force control device described in Patent Document 1 described above, the suppression or prevention of vehicle body vibration that may give a feeling of strangeness to the occupant due to the resonance frequency of the entire driving system is not considered. ..

The present invention has been made to solve the above problems, and is a control device for an all-wheel drive vehicle equipped with a transfer clutch that adjusts a driving force transmitted from an automatic transmission to a drive system on the slave drive wheel side. All-wheel drive that can prevent the occurrence of vehicle body vibration that may give the occupant a sense of discomfort due to the resonance frequency of the entire drive system without sacrificing fuel efficiency, responsiveness, cost, etc. The purpose is to provide a vehicle control device.

As a result of diligent studies on the above problems, the inventors have found that transient engine torque fluctuations due to steep operation of control devices such as opening and closing of tumble generator valves (TGVs) are caused by, for example, lockup dampers. When the torsional resonance of the drive system using the drive shaft as a spring is excited and the resonance frequency of the entire drive system and the primary component of tire rotation overlap or come close to each other, the strength of the front-rear G vibration is amplified, and as a result, It was found that it is recognized as a vehicle body vibration. A rotation order component that becomes one cycle when the tire makes one rotation is called a rotation primary component.

Therefore, the control device for the all-wheel drive vehicle according to the present invention is a control device for the all-wheel drive vehicle including a transfer clutch that adjusts the driving force transmitted from the automatic transmission to the drive system on the slave drive wheel side. A vehicle speed detecting means for detecting the vehicle speed of an all-wheel drive vehicle, a gear ratio acquisition means for acquiring a gear ratio of an automatic transmission, and a clutch control for controlling a transfer clutch engagement force based on the operating state of the all-wheel drive vehicle. The clutch control means includes means and a torque step generation predicting means for predicting whether or not a step occurs in the torque output from the engine and input to the entire drive system, and the clutch control means has a vehicle speed within a predetermined range and a transfer ratio. Is within a predetermined range, and the transfer clutch is released when it is predicted that a step will occur in the torque input to the entire drive system.

According to the control device for the all-wheel drive vehicle according to the present invention, it is predicted whether or not a step, that is, a steep fluctuation occurs in the torque output from the engine and input to the entire drive system, and the vehicle speed is within a predetermined range. Yes, the transfer clutch is released when the gear ratio is within a predetermined range and it is predicted that a step will occur in the torque input to the entire drive system. When the transfer clutch is released and the drive system on the upstream side and the drive system on the downstream side of the transfer clutch are separated, the components of the entire drive system are changed, and the resonance frequency of the entire drive system is changed. Therefore, the resonance of the entire drive system can be prevented, and the occurrence of vehicle body vibration that gives the occupant a sense of discomfort can be prevented. Further, in this case, the occurrence of vehicle body vibration can be prevented only by controlling the transfer clutch. As a result, it is possible to prevent the occurrence of vehicle body vibration that may give the occupant a sense of discomfort due to the eigenvalues of the entire drive system without sacrificing fuel efficiency, responsiveness, cost, and the like.

In the control device for the all-wheel drive vehicle according to the present invention, the torque step generation predicting means predicts that the drive state of the device that can cause a step in the torque output from the engine and input to the entire drive system is variable. It is preferable that the clutch control means release the transfer clutch before the device is driven when it is predicted that a step will occur in the torque and a step will occur in the torque.

In this case, it is possible to predict whether or not a step is generated in the torque from the driving state of the device which can cause a step in the torque output from the engine and input to the entire drive system. Further, since the transfer clutch is released before the device is driven, that is, before a step is generated in the torque, resonance of the entire drive system can be reliably avoided.

In the control device for the all-wheel drive vehicle according to the present invention, the device is a device capable of causing fluctuations in the output torque of the engine, and is at least one of a tumble generator valve, an exhaust gas recirculation device, and an injector. It is preferable to include one.

In this case, at least one of the tumble generator valve, the exhaust gas recirculation device, and the injector, which are devices that can cause fluctuations in the output torque of the engine, is scheduled to be driven / required, for example, opening / closing or valve opening time. It is possible to predict whether or not there will be a step in the torque from the change schedule / request.

In the control device for an all-wheel drive vehicle according to the present invention, the device is a device that is driven by an engine and can cause input torque fluctuations in the entire drive system, and is one of an air conditioner / compressor and an alternator. , At least one is preferably included.

In this case, at least one of the air conditioner / compressor and the alternator, which are devices driven by the engine and capable of causing fluctuations in the input torque to the entire drive system, is scheduled / required to be driven, for example, operating. -It is possible to predict whether or not there will be a step in torque from the schedule / request for stopping or switching the generated voltage.

In the control device for an all-wheel drive vehicle according to the present invention, it is preferable that the clutch control means permits the device to be driven after the transfer clutch is released.

In this case, the device is allowed to drive after the transfer clutch is released. That is, until the transfer clutch is released, the drive of the device that can cause a torque step is put into a standby state. Therefore, it is possible to reliably prevent vehicle body vibration.

The control device for an all-wheel drive vehicle according to the present invention is a control device for an all-wheel drive vehicle including a transfer clutch that adjusts a driving force transmitted from an automatic transmission to a drive system on the slave drive wheel side. A vehicle speed detecting means for detecting the vehicle speed of the driving vehicle, a gear ratio acquiring means for acquiring the gear ratio of the automatic transmission, and a clutch controlling means for controlling the engaging force of the transfer clutch based on the operating state of the all-wheel drive vehicle. The clutch control means is characterized in that the transfer clutch is released when the vehicle speed is within the predetermined speed range and the gear ratio is within the predetermined gear ratio range.

According to the control device for the all-wheel drive vehicle according to the present invention, the transfer clutch is released when the vehicle speed is within the predetermined speed range and the gear ratio is within the predetermined gear ratio range. Therefore, the transfer clutch is released when the vehicle body vibration can occur, for example, when the primary rotation of the tire and the resonance frequency of the entire drive system overlap or are close to each other. When the transfer clutch is released and the drive system on the upstream side and the drive system on the downstream side of the transfer clutch are separated, the components of the entire drive system are changed, and the eigenvalues of the entire drive system are changed. Therefore, the resonance of the entire drive system can be prevented, and the occurrence of vehicle body vibration that gives the occupant a sense of discomfort can be prevented. Further, in this case, the occurrence of vehicle body vibration can be prevented only by controlling the transfer clutch.

In the control device for an all-wheel drive vehicle according to the present invention, it is preferable that the clutch control means prohibits the release of the transfer clutch in a traveling situation where all-wheel drive is required.

In this case, the release of the transfer clutch is prohibited in the traveling situation where all-wheel drive is required. That is, the transfer clutch is released only when the vehicle is in a two-wheel drive environment. Therefore, for example, in a situation where all-wheel drive driving performance is required, such as on a frozen road or a split μ road, it is possible to give priority to ensuring all-wheel drive driving performance.

In the control device for the all-wheel drive vehicle according to the present invention, it is preferable that the clutch control means releases the lockup clutch of the torque converter instead of releasing the transfer clutch.

Even in this way, since the resonance frequency of the entire drive system can be changed, it is possible to prevent the occurrence of vehicle body vibration that gives the occupant a sense of discomfort.

Further, in the control device for the all-wheel drive vehicle according to the present invention, it is preferable that the clutch control means requests that the gear ratio of the automatic transmission be changed instead of or in addition to the release of the transfer clutch.

Even in this way, since the resonance frequency of the entire drive system can be changed, it is possible to prevent the occurrence of vehicle body vibration that gives the occupant a sense of discomfort.

According to the present invention, it is possible to prevent the occurrence of vehicle body vibration that may give the occupant a sense of discomfort due to the resonance frequency of the entire drive system without sacrificing fuel efficiency, responsiveness, cost, etc. Become.

It is a block diagram which shows the overall structure of the control device of the all-wheel drive vehicle which concerns on embodiment, and the power train and the driving force transmission system of the AWD vehicle equipped with the control device. It is a flowchart which shows the processing procedure of the vehicle body vibration prevention processing by the control device of the all-wheel drive vehicle which concerns on embodiment. It is a flowchart which shows the processing procedure of the vehicle body vibration prevention processing which concerns on the 2nd control mode.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

First, the configuration of the control device 1 of the all-wheel drive vehicle according to the embodiment will be described with reference to FIG. FIG. 1 shows a control device 1 of an all-wheel drive vehicle and a power train and a driving force transmission system (all drive system) 3 of an AWD (All Wheel Drive) vehicle 5 equipped with the control device 1. It is a block diagram which shows the structure. The AWD vehicle 5 according to the present embodiment is a part-time AWD vehicle equipped with a continuously variable transmission (hereinafter referred to as “CVT”) 30. In particular, the AWD vehicle 5 is a part-time AWD vehicle based on FF (Front engine Front drive).

The engine 20 may be of any type, and is, for example, a horizontally opposed in-cylinder injection type 4-cylinder gasoline engine. In the engine 20, the air sucked from the air cleaner (not shown) is throttled by an electronically controlled throttle valve (hereinafter, also simply referred to as “throttle valve”) 85 provided in the intake pipe, passes through the intake manifold, and passes through the engine 20. It is sucked into each cylinder formed in. Here, the amount of air sucked from the air cleaner is detected by the air flow meter. Further, the throttle valve 85 is provided with a throttle opening sensor 83 that detects the opening degree of the throttle valve 85. An injector 86 for injecting fuel is attached to each cylinder. Further, each cylinder is equipped with a spark plug that ignites the air-fuel mixture and a coil with a built-in igniter that applies a high voltage to the spark plug. In each cylinder of the engine 20, a mixture of the intake air and the fuel injected by the injector 86 is ignited by a spark plug and burned. The exhaust gas after combustion is discharged through the exhaust pipe.

In addition to the above-mentioned air flow meter and throttle opening sensor 83, a cam angle sensor 81 for discriminating the cylinder of the engine 20 is attached in the vicinity of the camshaft of the engine 20. Further, a crank angle sensor 82 for detecting the position of the crankshaft is attached in the vicinity of the crankshaft of the engine 20. These sensors are connected to an engine control unit (hereinafter referred to as "ECU") 80, which will be described later. Further, various sensors such as an accelerator opening sensor 84 that detects the amount of depression of the accelerator pedal, that is, the opening degree of the accelerator pedal, and a water temperature sensor that detects the temperature of the cooling water of the engine 20 are also connected to the ECU 80.

The above-mentioned intake pipe is provided with a tumble generator valve (hereinafter referred to as "TGV") 87. Further, the above-mentioned exhaust pipe is provided with an exhaust gas recirculation device (hereinafter referred to as "EGR (Exhaust Gas Recirculation)") 88. Further, the engine 20 is provided with an air conditioner compressor (hereinafter referred to as “A / C compressor”) 89, which is an auxiliary machine driven by the engine 20, an alternator 90, and the like.

Here, the injector 86 described above controls the valve opening time by the ECU 80 to operate the engine 20 in the vicinity of the excess air ratio λ of 1.0, that is, in the stoichiometric (hereinafter, simply referred to as “stoiki”) region. It switches between controlled stoichiometric control and lean burn control that controls the engine 20 in a region where the excess air ratio λ is larger than 1.0 (that is, a region where the amount of air is excessive with respect to the amount of fuel).

The TGV87 is a device that improves combustion by opening and closing according to, for example, an accelerator opening degree and changing the tumble ratio (tumble vortex). The drive (opening and closing) of the TGV 87 is controlled by the ECU 80.

The EGR88 is a device that recirculates (recirculates) a part of the exhaust gas discharged from the engine 20 to the intake system of the engine 20. The EGR88 includes an EGR pipe (not shown) that connects the exhaust pipe and the intake pipe of the engine 20 and an EGR valve (hereinafter, EGR) that is interposed on the EGR pipe and adjusts the exhaust gas recirculation amount (EGR flow rate). It has a valve 88). The opening degree of the EGR valve 88 is controlled by the ECU 80. As the EGR valve 88, in addition to the negative pressure type, a type driven by a stepping motor or the like can be used.

The A / C compressor 89 is driven by the engine 20 to compress the refrigerant. As the A / C compressor 89, it is preferable to use a variable displacement compressor capable of changing the amount of the refrigerant to be compressed. Here, a belt for transmitting a driving force is hung on a pulley (not shown) attached to one end of the crankshaft of the engine 20, and the A / C compressor 89 can be driven via the belt. It is connected to the. The operation / stop (or variable discharge amount) of the A / C compressor 89 is controlled by the ECU 80. The control of the A / C compressor 89 may be configured by using a dedicated A / C ECU instead of the ECU 80.

The alternator 90 is a generator that is driven by the engine 20 to generate electricity. The alternator 90 is a variable voltage alternator capable of varying the amount of power generation according to the electric load of the AWD vehicle 5. The switching of the amount of power generated by the alternator 90 is controlled by the ECU 80.

The output shaft (crankshaft) 21 of the engine 20 is a CVT 30 (patented) that converts and outputs the driving force from the engine 20 via a torque converter 22 having a clutch function and a torque amplification function and a forward / backward switching mechanism 27. (Equivalent to the automatic transmission described in the billing range) is connected.

The torque converter 22 is mainly composed of a pump impeller 23, a turbine runner 24, and a stator 25. The pump impeller 23 connected to the output shaft 21 creates a flow of oil, and the turbine runner 24 arranged to face the pump impeller 23 receives the power of the engine 20 via the oil to drive the output shaft. The stator 25 located between the two rectifies the discharge flow from the turbine runner 24 and reduces it to the pump impeller 23 to generate a torque amplification action.

Further, the torque converter 22 has a lockup clutch 26 that directly connects the input and the output. The torque converter 22 amplifies the driving force of the engine 20 and transmits it to the CVT 30 when the lockup clutch 26 is in the non-lockup state, and directly transfers the driving force of the engine 20 to the CVT 30 when the lockup clutch 26 is locked up. introduce. The rotation speed (turbine rotation speed) of the turbine runner 24 constituting the torque converter 22 is detected by the turbine rotation sensor 94. The detected turbine speed is output to a transmission control unit (hereinafter referred to as "TCU") 70, which will be described later.

The forward / backward switching mechanism 27 switches between forward rotation and reverse rotation (forward and reverse of the AWD vehicle 5) of the drive wheels 10 (left front wheel 10FL, right front wheel 10FR, left rear wheel 10RL, right rear wheel 10RR). The forward / backward switching mechanism 27 mainly includes a double pinion type planetary gear train, a forward clutch 28, and a reverse brake 29. The forward / backward switching mechanism 27 is configured to be able to switch the transmission path of the engine driving force by controlling the states of the forward clutch 28 and the reverse brake 29.

The CVT 30 has a primary shaft 32 connected to the turbine shaft of the torque converter 22 via a forward / backward switching mechanism 27, and a secondary shaft 37 arranged in parallel with the primary shaft 32. The primary shaft 32 is provided with a primary pulley 34. The primary pulley 34 has a fixed pulley 34a joined to the primary shaft 32 and a movable pulley 34b slidably mounted in the axial direction of the primary shaft 32 facing the fixed pulley 34a. The cone surface spacing of the pulleys 34a and 34b, that is, the pulley groove width can be changed. On the other hand, the secondary shaft 37 is provided with a secondary pulley 35. The secondary pulley 35 has a fixed pulley 35a joined to the secondary shaft 37 and a movable pulley 35b slidably mounted in the axial direction of the secondary shaft 37 facing the fixed pulley 35a, and has a pulley groove. It is configured so that the width can be changed.

A chain 36 for transmitting a driving force is hung between the primary pulley 34 and the secondary pulley 35. By changing the groove widths of the primary pulley 34 and the secondary pulley 35 and changing the ratio of the winding diameter of the chain 36 to the pulleys 34 and 35 (pulley ratio), the gear ratio is changed steplessly. Here, assuming that the winding diameter of the chain 36 with respect to the primary pulley 34 is Rp and the winding diameter of the chain 36 with respect to the secondary pulley 35 is Rs, the gear ratio i is represented by i = Rs / Rp. Therefore, the gear ratio i is obtained by dividing the primary pulley rotation speed Np by the secondary pulley rotation speed Ns (i = Np / Ns).

Here, a hydraulic chamber 34c is formed in the movable sheave 34b of the primary pulley 34. On the other hand, a hydraulic chamber 35c is formed in the movable sheave 35b of the secondary pulley 35. The groove widths of the primary pulley 34 and the secondary pulley 35 are set and changed by adjusting the primary oil pressure introduced into the hydraulic chamber 34c of the primary pulley 34 and the secondary oil pressure introduced into the hydraulic chamber 35c of the secondary pulley 35. Will be done.

The secondary shaft 37 of the CVT 30 is connected to the counter shaft 39 via a reduction gear 38 composed of a pair of reduction drive gears and reduction driven gears, and the driving force converted by the CVT 30 is countered via the reduction gear 38. It is transmitted to the shaft 39. The counter shaft 39 is connected to the front drive shaft 43 via a counter gear 40 composed of a pair of counter drive gears and counter driven gears. The driving force transmitted to the counter shaft 39 is transmitted to the front differential (hereinafter referred to as “front differential”) 44 via the counter gear 40 and the front drive shaft 43. The front differential 44 is, for example, a bevel gear type differential device. The driving force from the front differential 44 is transmitted to the left front wheel 10FL via the left front wheel drive shaft 45L and is transmitted to the right front wheel 10FR via the right front wheel drive shaft 45R.

On the other hand, a transfer clutch 41 for adjusting the driving force transmitted to the rear differential (hereinafter referred to as "rear differential") 47 is interposed in the rear stage of the counter gear 40 on the counter shaft 39 described above. The transfer clutch 41 controls the fastening force, that is, the torque distribution rate to the rear wheels (secondary drive wheels) 10RL and 10RR according to the driving state of the four wheels, for example, the slip state of the front wheels 10FL and 10FR, the engine torque, and the like. Therefore, the driving force transmitted to the counter shaft 39 is distributed according to the fastening force of the transfer clutch 41, and is also transmitted to the rear wheels 10RL and 10RR.

More specifically, the rear end of the counter shaft 39 is connected to the propeller shaft 46 extending to the rear of the vehicle via a transfer gear 42 composed of a pair of transfer drive gears and transfer driven gears. Therefore, the driving force transmitted to the counter shaft 39 and distributed by the transfer clutch 41 is transmitted from the transfer gear 42 to the rear differential 47 via the propeller shaft 46.

The left rear wheel drive shaft 48L and the right rear wheel drive shaft 48R are connected to the rear differential 47. The driving force from the rear differential 47 is transmitted to the left rear wheel 10RL via the left rear wheel drive shaft 48L and is transmitted to the right rear wheel 10RR via the right rear wheel drive shaft 48R.

By configuring the driving force transmission system of the power train as described above, for example, when the select lever is operated in the D range, the engine driving force is input to the primary shaft 32 of the CVT 30. The driving force converted by the CVT 30 is output from the secondary shaft 37 and transmitted to the front drive shaft 43 via the reduction gear 38, the counter shaft 39, and the counter gear 40. Then, the driving force is distributed to the left and right by the front differential 44 and transmitted to the left and right front wheels 10FL and 10FR. Therefore, the left and right front wheels 10FL and 10FR are always driven when the AWD vehicle 5 is in the traveling state.

On the other hand, a part of the driving force transmitted to the counter shaft 39 is transmitted to the propeller shaft 46 via the transfer clutch 41 and the transfer gear 42. Here, when a predetermined clutch torque is applied to the transfer clutch 41, the driving force distributed according to the clutch torque is output to the propeller shaft 46. Then, the driving force is also transmitted to the rear wheels 10RL and 10RR via the rear differential 47. As a result, the AWD vehicle 5 exhibits the function as an FF-based part-time AWD vehicle.

Each wheel 10FR to 10RR (hereinafter, all wheels 10FR to 19RR may be collectively referred to as wheel 10) each has brakes 11FR to 11RR (hereinafter, all brakes 11FR to 11RR) for braking the wheels 10FR to 10RR. (Sometimes collectively referred to as the brake 11) is attached. Further, wheel speed sensors 12FR to 12RR (hereinafter, all wheel speed sensors 12FR to 12RR may be collectively referred to as wheel speed sensors 12) for detecting wheel rotation speed are attached to each of the wheels 10FR to 10RR. ing.

The wheel speed sensor 12 is a non-contact type sensor that detects a change in a magnetic field due to a rotor that rotates with the wheel 10. For example, a semiconductor method that detects rotor rotation with a Hall element or MR element is preferably used.

The oil pressure for shifting the CVT 30, that is, the primary oil pressure and the secondary oil pressure described above are controlled by the valve body (control valve) 60. The valve body 60 adjusts the oil pressure discharged from the oil pump 62 by opening and closing the oil passage formed in the valve body 60 by using the spool valve and the solenoid valve that moves the spool valve, and the primary pulley 34. Supply to the hydraulic chamber 34c of the above and the hydraulic chamber 35c of the secondary pulley 35. Similarly, the valve body 60 adjusts the oil pressure discharged from the oil pump 62 by opening and closing the oil passage formed in the valve body 60 by using the spool valve and the solenoid valve 61 that moves the spool valve. , Supply hydraulic pressure to the transfer clutch 41 for engaging / releasing each clutch. Here, as the solenoid valve 61 for adjusting the hydraulic pressure supplied to the transfer clutch 41, for example, a duty solenoid capable of controlling the drive amount according to the duty ratio of the applied voltage is used.

The shift control of the CVT 30 is executed by the TCU 70. That is, the TCU 70 adjusts the oil supply to the hydraulic chamber 34c of the primary pulley 34 and the hydraulic chamber 35c of the secondary pulley 35 by controlling the drive of the solenoid valve constituting the valve body 60 described above, and shifts the CVT 30. Change the ratio. Similarly, the TCU 70 adjusts the oil supply to the transfer clutch 41 by controlling the drive of the solenoid valve 61 constituting the valve body 60 described above, and distributes the driving force transmitted to the rear wheels 10RL and 10RR. Adjust the ratio.

As described above, the shift control of the CVT 30 and the engagement / release control (driving force distribution control) of the transfer clutch 41 are executed by the TCU 70. Here, the TCU 70 is connected to the TCU 70 via, for example, a CAN (Control Area Network) 100 so as to be communicable with an ECU 80 or the like that comprehensively controls the engine 20.

The TCU 70 and the ECU 80 are stored by, for example, a microprocessor that performs calculations, an EEPROM that stores a program for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, and a battery. It is configured to have a backup RAM for holding the contents, an input / output I / F, and the like.

The ECU 80 drives an injector driver that drives the injector 86, an output circuit that outputs an ignition signal, a motor driver that drives an electric motor that opens and closes an electronically controlled throttle valve 85, a driver that drives the TGV 87, and an EGR valve 88. It is equipped with a driver, etc. In the ECU 80, the cylinder is determined from the output of the cam angle sensor 81, and the engine speed is obtained from the change in the rotation position of the crankshaft detected by the output of the crank angle sensor 82. Further, the ECU 80 acquires various information such as the intake air amount, the accelerator pedal opening degree, the air-fuel ratio of the air-fuel mixture, and the water temperature based on the detection signals input from the various sensors described above. Then, the ECU 80 comprehensively controls the engine 20 by controlling the fuel injection amount, the ignition timing, and various devices such as the throttle valve 85, the TGV87, and the EGR valve 88 based on the acquired various information. .. Further, the ECU 80 controls the drive of devices such as the A / C compressor 89 and the alternator 90.

Further, the ECU 80 transmits various information such as the accelerator pedal opening degree, the engine speed, and the engine shaft torque to the TCU 70 via the CAN 100. Further, the ECU 80 transmits information indicating the current drive state of the injector 86, the TGV87, and the EGR valve 88 via the CAN100, and changes in future drive schedules / requests (for example, opening / closing and valve opening time (stoichi / lean)). Information indicating the schedule / request), information indicating the current drive state of the A / C compressor 89 and the alternator 90, and future drive schedule / request (for example, schedule / request for operation / stop and power generation voltage switching). Information and the like indicating the above are transmitted to the TCU 70.

In addition to the turbine rotation sensor 94 described above, the TCU 70 includes an oil temperature sensor 91 that detects the oil temperature of the CVT 30, a secondary shaft rotation sensor 92 that detects the rotation speed of the secondary shaft 37, and a range that detects the selected position of the shift lever. A switch 93 or the like is connected. The secondary shaft rotation sensor 92 functions as the vehicle speed detecting means described in the claims.

Further, as described above, the TCU 70 receives information such as the accelerator pedal opening degree, the engine speed, and the engine shaft torque (output torque) from the ECU 80 via the CAN 100. Further, the TCU 70 provides information indicating the current drive state of the injector 86, the TGV 87, and the EGR valve 88 from the ECU 80 via the CAN 100, as well as future drive schedules / requests (for example, opening / closing and valve opening time (stoichi / lean)). ) Information indicating the change schedule / request), information indicating the current drive state of the A / C compressor 89 and the alternator 90, and future drive schedule / request (for example, start / stop and power generation voltage switching schedule). -Receive information indicating the request).

The TCU 70 automatically shifts the gear ratio steplessly according to the driving state of the AWD vehicle 5 (for example, accelerator opening and vehicle speed) according to the shift map. The shift map is stored in EEPROM or the like in the TCU 70.

Further, the TCU 70 executes transfer clutch control (driving force distribution control) based on various information acquired from the various sensors and the like described above. By the way, for example, transient engine torque fluctuation due to abrupt operation of a control device such as opening / closing of TGV87 causes torsional resonance of a drive system using, for example, a lockup damper (not shown) or a drive shaft 43, 45, 48 as a spring. When the drive system resonance and the tire rotation primary overlap or come close to each other, the strength of the front-rear G vibration is amplified, which may cause a loose vehicle body vibration.

Therefore, the TCU 70 is caused by the eigenvalues (resonance frequency, for example, about several Hz) of the entire drive system 3 without sacrificing fuel consumption, responsiveness, cost, etc., and can give the occupant a sense of discomfort. It has a function to prevent the occurrence. Therefore, the TCU 70 functionally has a gear ratio acquisition unit 71, a torque step generation prediction unit 72, and a transfer clutch control unit 73. In the TCU 70, the functions of the gear ratio acquisition unit 71, the torque step generation prediction unit 72, and the transfer clutch control unit 73 are realized by executing the program stored in the EEPROM or the like by the microprocessor.

The gear ratio acquisition unit 71 acquires the gear ratio of the CVT 30. That is, the gear ratio acquisition unit 71 functions as the gear ratio acquisition means described in the claims. More specifically, the gear ratio acquisition unit 71 obtains the gear ratio i by dividing the primary pulley rotation speed Np by the secondary pulley rotation speed Ns (i = Np / Ns). The acquired gear ratio is output to the torque step generation prediction unit 72.

The torque step generation prediction unit 72 predicts whether or not a step, that is, a steep fluctuation occurs in the torque output from the engine 20 (driving force source) and input to the entire drive system 3. That is, the torque step generation prediction unit 72 functions as the torque step generation prediction means described in the claims. At that time, the torque step generation prediction unit 72 predicts that, for example, the drive state of the device that can cause a step in the torque output from the engine 20 and input to the entire drive system 3 is changed. , It is predicted that a step will occur in the torque.

Here, the device is a device that can cause an output torque fluctuation of the engine 20, and in the present embodiment, the injector 86, the TGV 87, and the EGR valve 88 described above are applicable. Further, the above-mentioned device is a device that is driven by the engine 20 and can cause an input torque fluctuation to the entire drive system 3, and in the present embodiment, the above-mentioned A / C compressor 89 and the alternator 90 are applicable. To do.

More specifically, the torque step generation prediction unit 72 indicates information indicating the drive schedule / request of the injector 86, TGV87, and EGR valve 88 (for example, change schedule / request of opening / closing or valve opening time (stoichi / lean)). In addition, based on the information indicating the drive schedule / request of the A / C compressor 89 and the alternator 90 (for example, the schedule / request of operation / stop and power generation voltage switching), the torque input to the entire drive system 3 is stepped. , Predict whether steep fluctuations will occur. That is, the torque step generation prediction unit 72 predicts that a step will occur in the torque input to the entire drive system 3 when the valve opening time of the injector 86 is scheduled to be changed. Further, when the torque step generation prediction unit 72 is scheduled to be driven from the valve closed state to the valve open state or from the valve open state to the closed state, the torque step generation prediction unit 72 is applied to the entire drive system 3. It is predicted that there will be a step in the input torque. Similarly, the torque step generation prediction unit 72 predicts that a step will occur in the torque input to the entire drive system 3 when the valve opening degree of the EGR valve 88 is scheduled to be changed.

Further, the torque step generation prediction unit 72 drives the drive system when the A / C compressor 89 is changed from a stopped state to an operating state, from a movable state to a stopped state, or when the capacitance is variable. It is predicted that there will be a step in the torque input to all systems 3. Further, the torque step generation prediction unit 72 predicts that a step will occur in the torque input to the entire drive system 3 when the power generation amount of the alternator 90 is scheduled to be changed or switched. The prediction result of whether or not a step is generated in the torque is output to the transfer clutch control unit 73.

The transfer clutch control unit 73 determines the fastening force of the transfer clutch 41 (that is, the driving force distribution rate to the rear wheels 10RL and 10RR) based on the operating state of the AWD vehicle 5 (for example, the driving state of the four wheels, the engine torque, etc.). Is controlled in real time. That is, the transfer clutch control unit 73 functions as the clutch control means described in the claims.

In particular, the transfer clutch control unit 73 has a vehicle speed within a predetermined range and a gear ratio within a predetermined range (that is, the primary rotation of the tire and the resonance frequency of the entire drive system 3 overlap or are close to each other. The oil pressure is adjusted so as to release the transfer clutch 41 when it is predicted that the torque input to the entire drive system 3 will have a step (in a traveling state where vehicle body vibration can occur).

At that time, that is, when the vehicle speed is within the predetermined range, the gear ratio is within the predetermined range, and it is predicted that a step will occur in the torque input to the entire drive system 3, the transfer clutch control unit. 73 releases the transfer clutch 41 in advance before the drive state of the device (injector 86, TGV 87, EGR valve 88, A / C compressor 89, alternator 90 in this embodiment) is changed.

Further, when the transfer clutch 41 is released, the transfer clutch control unit 73 permits the drive of the device after that, that is, after the transfer clutch 41 is released. That is, the transfer clutch control unit 73 puts the drive of the device in a standby state until the transfer clutch 41 is released. Further, the transfer clutch control unit 73 is permitted to drive the device, and after the device is driven, engages the transfer clutch 41 (that is, returns to normal control).

However, for example, in a situation where running performance in all-wheel drive such as a frozen road or a split μ road is required, the transfer clutch control unit 73 has a predetermined vehicle speed in order to give priority to ensuring running performance in all-wheel drive. Even if it is within the range, the gear ratio is within the predetermined range, and it is predicted that a step will occur in the torque input to the entire drive system 3, the release of the transfer clutch 41 is prohibited. That is, the transfer clutch control unit 73 releases the transfer clutch 41 only when the vehicle is in a two-wheel drive environment.

Next, the operation of the control device 1 of the all-wheel drive vehicle will be described with reference to FIG. FIG. 2 is a flowchart showing a processing procedure of vehicle body vibration prevention processing by the control device 1 of the all-wheel drive vehicle. This process is repeatedly executed at a predetermined timing mainly in the TCU 70. Here, it is assumed that the transfer clutch 41 is engaged and the transfer clutch 41 can be released, that is, a traveling situation in which two-wheel drive may be used.

In step S100, the vehicle speed is obtained from the change in the rotation position of the output shaft 37 detected by the output of the secondary shaft rotation sensor 92. In the following step S102, the gear ratio i is obtained by dividing the primary pulley rotation speed Np by the secondary pulley rotation speed Ns (i = Np / Ns).

Next, in step S104, it is determined whether or not the vehicle speed is within the predetermined range and the gear ratio is within the predetermined range. Here, when both conditions are satisfied (that is, when the resonance frequencies of the primary rotation of the tire and the entire drive system 3 are overlapped or close to each other and the vehicle body vibration can occur). The process shifts to step S106. On the other hand, if either condition or both conditions are not satisfied, the process is temporarily exited.

In step S106, information indicating the drive schedule / request of the injector 86, TGV87, and EGR valve 88 (for example, change schedule / request of opening / closing and valve opening time (stoichi / lean)), A / C compressor 89, and alternator 90 Information indicating the drive schedule / request (for example, start / stop or power generation voltage switching schedule / request) is acquired.

Subsequently, in step S108, based on the information indicating the drive schedule / request of the injector 86, the TGV 87, and the EGR valve 88 acquired in step S106, and the information indicating the drive schedule / request of the A / C compressor 89 and the alternator 90. Therefore, it is predicted whether or not a step, that is, a steep fluctuation occurs in the torque input to the entire drive system 3. Since the method for predicting the torque step is as described above, detailed description thereof will be omitted here.

Next, in step S110, it is determined whether or not it is predicted that a step will occur in the torque input to the entire drive system 3. Here, if it is predicted that a step will occur in the torque, the process shifts to step S112. On the other hand, when it is not predicted that a step will occur in the torque, the process is temporarily exited.

In step S112, the transfer clutch 41 is released. It should be noted that the change of the drive state of the devices (injector 86, TGV 87, EGR valve 88, A / C compressor 89, and / or alternator 90) is prohibited until the release of the transfer clutch 41 is completed. After that, that is, after the release of the transfer clutch 41 is completed, in step S114, the devices (injector 86, TGV87, EGR valve 88, A / C) whose drive state is prohibited from being changed until the release of the transfer clutch 41 is completed. Driving of the compressor 89 and / or the alternator 90) is permitted.

Subsequently, in step S116, it is determined whether or not the driving of the device permitted to be driven in step S114 is completed. Here, if the drive of the device is not completed, this step is repeatedly executed until the drive of the device is completed. On the other hand, when the driving of the device is completed, the process shifts to step S118.

In step S118, the transfer clutch 41 is engaged (that is, returns to normal control). After that, the process is temporarily exited.

In addition, instead of or in addition to the above-mentioned flowchart, the vehicle body vibration prevention process may be executed according to the flowchart shown in FIG. Here, FIG. 3 is a flowchart showing a processing procedure of the vehicle body vibration prevention processing according to the second control mode. More specifically, as shown in FIG. 3, when the vehicle speed is within the predetermined speed range and the gear ratio is within the predetermined gear ratio range (when step S204 is affirmed), that is, for example, for example. The transfer clutch 41 may be released (step S206) when the primary rotation of the tire and the resonance frequencies of the entire drive system 3 overlap or are close to each other. In that case, the vehicle speed condition (predetermined speed range) and the gear ratio condition (predetermined gear ratio range) may be different from those in the flowchart shown in FIG. 2, or may be the same. Good. However, when both conditions are the same, the processing after step S106 of the flowchart shown in FIG. 2 becomes unnecessary. Since the other processing contents are the same as the processing contents of the flowchart shown in FIG. 2, detailed description thereof will be omitted here.

As described in detail above, according to the present embodiment, it is predicted whether or not a step, that is, a steep fluctuation occurs in the torque output from the engine 20 and input to the entire drive system 3, and the vehicle speed is predetermined. The transfer clutch 41 is released when it is within the range, the gear ratio is within the predetermined range, and it is predicted that a step will occur in the torque input to the entire drive system 3. When the transfer clutch 41 is released and the drive system on the upstream side and the drive system on the downstream side of the transfer clutch 41 are separated, the components of the entire drive system 3 are changed, and the resonance frequency of the entire drive system 3 is changed. Changes. Therefore, the resonance of the entire drive system 3 can be prevented, and the occurrence of vehicle body vibration that gives the occupant a sense of discomfort can be prevented. Further, in this case, the occurrence of vehicle body vibration can be prevented only by controlling the transfer clutch 41. As a result, it is possible to prevent the occurrence of vehicle body vibration that may give the occupant a sense of discomfort due to the resonance frequency of the entire drive system 3 without sacrificing fuel consumption, responsiveness, cost, and the like.

According to the present embodiment, a device capable of causing a step in the torque output from the engine 20 and input to the entire drive system 3 (in the present embodiment, an injector 86, a TGV 87, an EGR valve 88, an A / C compressor 89). , It is possible to predict whether or not a step is generated in the torque from the driving state of the alternator 90). Further, since the transfer clutch 41 is released before the device is driven (that is, before a step is generated in the torque), resonance of the entire drive system 3 can be reliably avoided.

According to the present embodiment, at least one of the injector 86, the TGV 87, and the EGR valve 88, which are devices capable of causing the output torque fluctuation of the engine 20, is scheduled to be driven / required (for example, opening / closing or opening / closing). It is possible to predict whether or not there will be a step in the torque from the time change schedule / request).

Further, according to the present embodiment, at least one of the A / C compressor 89 and the alternator 90, which are devices driven by the engine 20 and capable of causing input torque fluctuations to the entire drive system 3, is used. It is possible to predict whether or not there is a step in torque from one drive schedule / request, for example, a schedule / request for operation / stop or power generation voltage switching.

According to this embodiment, the device is allowed to be driven after the transfer clutch 41 is released. That is, until the transfer clutch 41 is released, the drive of the device that can cause a torque step is put into a standby state. Therefore, it is possible to reliably prevent vehicle body vibration.

According to the present embodiment, the transfer clutch 41 is prohibited from being released in a traveling situation where all-wheel drive is required. That is, the transfer clutch 41 is released only when the vehicle is in a two-wheel drive environment. Therefore, for example, in a situation where all-wheel drive driving performance is required, such as on a frozen road or a split μ road, it is possible to give priority to ensuring all-wheel drive driving performance.

If the vehicle speed is within the predetermined speed range and the gear ratio is within the predetermined gear ratio range, and the transfer clutch 41 is released, the primary rotation of the tire and the resonance of the entire drive system 3 are resonated. The transfer clutch 41 is released when the frequencies overlap or are close to each other and the vehicle body vibration can occur. In this case, since it is not necessary to predict whether or not a step, that is, a steep fluctuation occurs in the torque input to the entire drive system 3, the resonance of the entire drive system 3 is avoided while reducing the processing load of the ECU 80. As a result, it is possible to prevent the occurrence of vehicle body vibration that gives the occupant a sense of discomfort.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways. For example, in the above embodiment, the transfer clutch 41 is controlled (released) in order to prevent vehicle body vibration by changing the resonance frequency of the entire drive system 3, but instead of releasing the transfer clutch 41, the torque converter 22 The lockup clutch 26 may be controlled (released). Further, instead of or in addition to releasing the transfer clutch 41, the gear ratio of the CVT 30 may be changed (changed to the OD side). Even with such a configuration, since the resonance frequency of the entire drive system 3 can be changed, it is possible to prevent the occurrence of vehicle body vibration that gives the occupant a sense of discomfort.

Further, in the above embodiment, injector 86, TGV87, and EGR valve 88 are mentioned as devices that can cause output torque fluctuation of the engine 20, and are driven by the engine 20 to cause input torque fluctuation to the entire drive system 3. As the device to be obtained, the A / C compressor 89 and the alternator 90 have been mentioned, but these devices are examples, and other devices may be used. Further, the device to be used may be any one or may be arbitrarily combined.

In the above embodiment, the chain type continuously variable transmission has been described as an example of the automatic transmission, but instead of the chain type continuously variable transmission, for example, a belt type continuously variable transmission or a toroidal type continuously variable transmission has been described. A continuously variable transmission may be used. Further, a stepped automatic transmission (step AT) or the like can be used instead of the continuously variable transmission.

Further, the configuration of the entire drive system 3 described above (for example, arrangement of gears, shafts, etc.) is an example, and is not limited to the above embodiment. Further, in the above embodiment, the duty solenoid is used as the solenoid valve for adjusting the oil pressure, but a linear solenoid or the like can be used instead of the duty solenoid.

Further, in the above embodiment, the transfer clutch 41 is controlled by the TCU 70, but it may be controlled by a dedicated AWD controller independent of the TCU 70. Further, the system configuration is not limited to the above embodiment.

1 All-wheel drive vehicle control device 3 Driving force transmission system (all drive system)
5 AWD vehicle 10FL, 10FR, 10RL, 10RR Wheel 20 Engine 22 Torque converter 26 Lockup clutch 27 Forward / backward switching mechanism 30 Continuously variable transmission (CVT)
32 Primary shaft 34 Primary pulley 35 Secondary pulley 36 Chain 37 Secondary shaft 38 Reduction gear 41 Transfer clutch 60 Control valve (valve body)
61 Solenoid valve 70 TCU
71 Gear ratio acquisition unit 72 Torque step generation prediction unit 73 Transfer clutch control unit 80 ECU
81 Cam angle sensor 82 Crank angle sensor 83 Throttle opening sensor 84 Accelerator opening sensor 85 Electronically controlled throttle valve 86 Injector 87 Tumble generator valve (TGV)
88 EGR valve 89 Air conditioner compressor 90 Alternator 91 Oil temperature sensor 92 Secondary shaft rotation sensor 93 Range switch 94 Turbine rotation sensor 100 CAN

Claims (9)

It is a control device for all-wheel drive vehicles equipped with a transfer clutch that adjusts the driving force transmitted from the automatic transmission to the drive system on the slave drive wheel side.
A vehicle speed detecting means for detecting the vehicle speed of the all-wheel drive vehicle and
A gear ratio acquisition means for acquiring the gear ratio of the automatic transmission, and
A clutch control means for controlling the engaging force of the transfer clutch based on the operating state of the all-wheel drive vehicle, and
It is equipped with a torque step generation predicting means for predicting whether or not a step is generated in the torque output from the engine and input to the entire drive system.
The clutch control means transfers the transfer when it is predicted that the vehicle speed is within a predetermined range, the gear ratio is within a predetermined range, and a step is generated in the torque input to the entire drive system. A control device for all-wheel drive vehicles characterized by releasing the clutch. The torque step generation predicting means causes a step in the torque when it is predicted that the drive state of a device that can generate a step in the torque output from the engine and input to the entire drive system is variable. Predict that it will occur,
The all-wheel drive vehicle according to claim 1, wherein the clutch control means releases the transfer clutch before the device is driven when it is predicted that a step is generated in the torque. Control device. 2. The device is a device capable of causing output torque fluctuation of the engine, and includes at least one of a tumble generator valve, an exhaust gas recirculation device, and an injector. The control device for all-wheel drive vehicles described. The device is a device driven by the engine and capable of causing input torque fluctuation to the entire drive system, and is characterized by including at least one of an air conditioner compressor and an alternator. The control device for an all-wheel drive vehicle according to claim 2 or 3. The control device for an all-wheel drive vehicle according to any one of claims 2 to 4, wherein the clutch control means permits driving of the device after releasing the transfer clutch. It is a control device for all-wheel drive vehicles equipped with a transfer clutch that adjusts the driving force transmitted from the automatic transmission to the drive system on the slave drive wheel side.
A vehicle speed detecting means for detecting the vehicle speed of the all-wheel drive vehicle and
A gear ratio acquisition means for acquiring the gear ratio of the automatic transmission, and
A clutch control means for controlling the engaging force of the transfer clutch based on the operating state of the all-wheel drive vehicle is provided.
The clutch control means is a control device for an all-wheel drive vehicle, which releases the transfer clutch when the vehicle speed is within a predetermined speed range and the gear ratio is within a predetermined gear ratio range. .. The all-wheel drive vehicle according to any one of claims 1 to 6, wherein the clutch control means prohibits the release of the transfer clutch in a traveling situation where all-wheel drive is required. Control device. The control device for an all-wheel drive vehicle according to any one of claims 1 to 7, wherein the clutch control means releases the lockup clutch of the torque converter instead of releasing the transfer clutch. The all-wheel according to any one of claims 1 to 7, wherein the clutch control means changes the gear ratio of the automatic transmission in place of or in addition to releasing the transfer clutch. Drive vehicle control device.

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